is fixed by Sir W. Thomson at 300 millions of years by refnge- 
ration • at 500 millions of years by the calculated age of solar 
heat “’and at 100 millions of years by the retardation of the 
68 ’ll S The first-named cause may be considered to be properly 
within the limits of geological inquiry. The actu J C °“?°te»ra- 
of the earliest sedimentary rocks, derived from the tbsintegra 
tion of igneous products, and the outbursts of molten rock in 
Xperiods of the earth’s history, point to a primitive mo ten 
condition of the globe. The state of the deposits proves that 
as the earth became cool it occasioned precipitation of watei on a 
large scale. There is no trace of any repetition °f these pheno- 
mena The present state of things is not the result of an e e 
lasting play of forces between the heat of the earth and the 
condition of the atmosphere, but of a law operating o pro- 
duce further progress. The effect of modern volcanic action, 
thoughtending in the direction of restormg the wasting an 
levelling processes of meteoric causes, is yet on \ a ieal ^ a J 
phenomenon of that which was once so potent It is now 
tinv force compared with the power exerted by an and wate . 
fa The action of the carbonic acid of the atmosphere on 
the present crust of the earth is slowly to deco “P°mechXai 
integrate the latter, leaving it a ready pr^ to the 
forces of denudation. Chemists assure us that this ^ hut a 
feeble representation of the greater power which arose from 
o-reater volume of carbonic acid during the early history ot the 
earth • that all the carbonic acid, all the chlorine, all the sulphu , 
once existed in the atmosphere, -a state of things towards 
which there is certainly no proof of any tendency to recur.* 
13 If all the force of the solar system is gradually becoming 
changed into heat, and if some of that heat remains on the 
earth’s surface not reconverted into force, things mus come 
an end. All differences of temperature at the earth ■ «« a - 
will ultimately he merged in universal heat. The conclusio 
may be stated in the language of Adolt hick : 
« We are come to this alternative : either in our highest, our most general, 
our most fundamental scientific abstractions, some great P°f Ms ^ n °Z 
looked ; or the universe wifi have an end and must have had a hegnnu^ , 
could not have existed from Eternity, but must at some date uot mfimUy 
distant have arisen from something not forming part of the chain of nature 
causes, i.e. must have been cveatcd. 
14. If progress in the physical world is admitted, I do not see 
how the notion of a beginning, and of a Creator, can be avoided. 
* See Sterry Hunt’s Lecture at Loyal Institution, May 31st, 1867. 
